Wireless Local Area Network Discovery and Selection Method, Device, and System, and Terminal

1. A wireless local area network discovery and selection method, comprising: scanning wireless local area networks and acquiring a first wireless access point list, wherein the first wireless access point list comprises at least one wireless access point identifier and signal strength of each wireless access point in the at least one wireless access point identifier; sending a registration request to a wireless local area network discovery and selection device when packet switched data is initiated to a cellular network, wherein the registration request carries location information of a terminal and the first wireless access point list; receiving a notification message sent by the wireless local area network discovery and selection device, wherein the notification message carries access parameter information, wherein the access parameter information comprises an offload policy message and a second wireless access point list, wherein the second wireless access point list is acquired by the wireless local area network discovery and selection device by: acquiring attribute information of each wireless access point in all wireless access point identifiers corresponding to the location information of the terminal upon reception of the registration request, the attribute information being acquired from one or more access controllers that correspond to the each wireless access point in all the wireless access point identifiers corresponding to the location information of the terminal, wherein the attribute information comprises at least one of a signal-to-noise ratio, a load, and throughput; and identifying availability of each wireless access point according to the attribute information of each wireless access point in all the wireless access point identifiers corresponding to the location information of the terminal, wherein the second wireless access point list comprises at least one wireless access point identifier available for access by the terminal and attribute information of each wireless access point available for access by the terminal; and selecting, according to the access parameter information, a target wireless access point, wherein selecting the target wireless access point according to the access parameter information comprises selecting, according to the offload policy message, the target wireless access point from the second wireless access point list, wherein the offload policy message is used to instruct to select a wireless access point with a highest signal strength, select a wireless access point with a smallest load, or select a wireless access point in a preset frequency band.

2. The method according to claim 1 , wherein selecting the target wireless access point further comprises selecting, according to the offload policy message, the target wireless access point from the second wireless access point list and the target wireless access point and from the first wireless access point list.

3. The method according to claim 2 , wherein the at least one wireless access point identifier available for access by the terminal in the second wireless access point list comprises a service set identifier of a wireless access point of an available wireless local area network; the first wireless access point list further comprises a service set identifier of each wireless access point in the at least one wireless access point identifier of the first wireless access point list; and wherein selecting the target wireless access point comprises selecting, according to the offload policy message, the service set identifier of the wireless access point of the wireless local area network of the second wireless access point list, and the first wireless access point list, the target wireless access point from the second wireless access point list and from the first wireless access point list.

4. The method according to claim 1 , wherein selecting the target wireless access point comprises selecting, according to the offload policy message, the target wireless access point from an intersection of the first wireless access point list and the second wireless access point list.

5. The method according to claim 1 , wherein after selecting the target wireless access point according to the access parameter information, the method further comprises determining, when the target wireless access point is not detected within a first preset time segment, that offload fails, and disabling a Wireless Fidelity function; or the method further comprises disabling the Wireless Fidelity function when no data traffic of the packet switched data is detected within a second preset time segment; or the method further comprises: detecting, when the wireless local area network can be accessed by using the target wireless access point, a speed in the wireless local area network; determining whether the speed is lower than a preset speed threshold; and in response to determining that the speed is lower than the preset speed threshold, disabling the Wireless Fidelity function.

6. A wireless local area network discovery and selection method, comprising: receiving a registration request sent by a terminal, wherein the registration request is initiated when the terminal initiates packet switched data to a cellular network; after receiving the registration request sent by the terminal and before acquiring any access parameter information, determining whether the packet switched data in the cellular network needs to be offloaded, wherein determining whether the packet switched data in the cellular network needs to be offloaded comprises: acquiring, from a home location register, a priority of a user of the terminal; determining whether the priority of the user of the terminal is higher than or equal to a preset priority threshold; when the priority of the user of the terminal is higher than or equal to the preset priority threshold, determining that the packet switched data in the cellular network does not need to be offloaded; and when the priority of the user of the terminal is not higher than or equal to the preset priority threshold determining that the packet switched data in the cellular network may needs to be offloaded; acquiring the access parameter information in response to determining that the packet switched data in the cellular network needs to be offloaded; and sending a notification message carrying the access parameter information to the terminal so that the terminal selects, according to the access parameter information, a target wireless access point.

7. The method according to claim 6 , wherein determining whether the packet switched data in the cellular network needs to be offloaded further comprises: acquiring, from a network element in the cellular network or a network element in a core network, a service type of the packet switched data; and determining, according to the service type, whether the packet switched data in the cellular network needs to be offloaded.

8. The method according to claim 6 , wherein acquiring the access parameter information comprises acquiring an offload policy message, wherein the offload policy message is used to instruct to select a wireless access point with a highest signal strength or select a wireless access point in a preset frequency band; and wherein sending the notification message carrying the access parameter information to the terminal comprises sending a notification message carrying the offload policy message to the terminal, so that the terminal scans wireless local area networks, acquires a first wireless access point list, wherein the first wireless access point list comprises at least one wireless access point identifier and signal strength of each wireless access point or a frequency band of each wireless access point, and selects, according to the offload policy message, the target wireless access point from the first wireless access point list.

9. The method according to claim 6 , wherein acquiring the access parameter information comprises acquiring an offload policy message and a service set identifier of a wireless access point of a wireless local area network available for access by the terminal, wherein the offload policy message is used to instruct to select a wireless access point with a highest signal strength or select a wireless access point in a preset frequency band; and wherein sending the notification message carrying the access parameter information to the terminal comprises sending a notification message carrying the offload policy message and carrying the service set identifier of the wireless access point of the wireless local area network to the terminal, so that the terminal scans wireless local area networks, acquires a first wireless access point list, wherein the first wireless access point list comprises at least one wireless access point identifier, a service set identifier of a wireless access point of a wireless local area network corresponding to each wireless access point, and signal strength of each wireless access point or a frequency band of each wireless access point or both, and selects, according to the offload policy message, the service set identifier of the wireless access point of the wireless local area network, and the first wireless access point list, the target wireless access point from the first wireless access point list.

10. The method according to claim 6 , wherein the registration request carries location information of the terminal; wherein acquiring the access parameter information comprises: acquiring all wireless access point identifiers corresponding to the location information of the terminal; acquiring attribute information of each wireless access point in all the wireless access point identifiers corresponding to the location information of the terminal, wherein the attribute information comprises at least one of a signal-to-noise ratio, a load, and throughput; and identifying availability of each wireless access point according to the attribute information corresponding to each wireless access point in all the wireless access point identifiers corresponding to the location information of the terminal, acquiring a second wireless access point list, wherein the second wireless access point list comprises at least one wireless access point identifier available for access by the terminal and attribute information of each wireless access point available for access by the terminal, and acquiring a preset offload policy message, wherein the preset offload policy message is used to instruct to select a wireless access point with a highest signal strength, select a wireless access point with a smallest load, or select a wireless access point in a preset frequency band; and wherein sending the notification message carrying the access parameter information to the terminal comprises sending a notification message carrying offload policy information and carrying the second wireless access point list to the terminal, so that the terminal scans wireless local area networks, acquires a first wireless access point list, wherein the first wireless access point list comprises at least one wireless access point identifier, and selects, according to the offload policy message, the target wireless access point from an intersection of the first wireless access point list and the second wireless access point list.

11. The method according to claim 10 , wherein acquiring the attribute information of each wireless access point in all the wireless access point identifiers corresponding to the location information of the terminal comprises: acquiring, from prestored attribute information of wireless access points in all access controllers, the attribute information of each wireless access point in all the wireless access point identifiers corresponding to the location information of the terminal; or interacting, according to all the wireless access point identifiers corresponding to the location information of the terminal, with an access controller corresponding to each wireless access point identifier and acquiring the attribute information of each wireless access point in all the wireless access point identifiers corresponding to the location information of the terminal.

12. The method according to claim 6 , wherein the registration request carries a first wireless access point list, wherein the first wireless access point list is acquired by the terminal by scanning wireless local area networks and the first wireless access point list comprises at least one wireless access point identifier; wherein acquiring the access parameter information comprises: acquiring attribute information corresponding to each wireless access point identifier, wherein the attribute information comprises at least one of a signal-to-noise ratio, a load, and throughput; identifying availability of each wireless access point according to the attribute information corresponding to each wireless access point identifier in the first wireless access point list, and selecting a second wireless access point list from the first wireless access point list, wherein the second wireless access point list comprises at least one wireless access point identifier available for access by the terminal and attribute information of each wireless access point available for access by the terminal; and acquiring a preset offload policy information, wherein offload policy message is used to instruct to select a wireless access point with a highest signal strength, select a wireless access point with a smallest load, or select a wireless access point in a preset frequency band; and wherein sending the notification message carrying the access parameter information to the terminal comprises sending a notification message carrying the offload policy information and carrying the second wireless access point list to the terminal, so that the terminal selects, according to the offload policy message, to the target wireless access point from the second wireless access point list.

13. The method according to claim 6 , wherein the registration request carries a first wireless access point list; wherein the first wireless access point list is acquired by the terminal by scanning wireless local area networks and the first wireless access point list comprises at least one wireless access point identifier; wherein acquiring the access parameter information comprises: acquiring attribute information corresponding to each wireless access point identifier, wherein the attribute information comprises at least one of a signal-to-noise ratio, a load, and throughput; identifying availability of each wireless access point according to the attribute information corresponding to each wireless access point identifier in the first wireless access point list, and selecting a second wireless access point list from the first wireless access point list, wherein the second wireless access point list comprises at least one wireless access point identifier available for access by the terminal and attribute information of each wireless access point available for access by the terminal; and acquiring, according to a preset offload policy information, an identifier of the target wireless access point from the second wireless access point list, wherein offload policy message is used to instruct to select a wireless access point with a smallest load or select a wireless access point in a preset frequency band; and wherein sending the notification message carrying the access parameter information to the terminal comprises sending a notification message carrying the identifier of the target wireless access point to the terminal.

14. A terminal, comprising: a transmitter, configured to send, when packet switched data is initiated to a cellular network, a registration request to a wireless local area network discovery and selection device, wherein the registration request carries location information of the terminal to the wireless local area network discovery and selection device; a receiver, configured to receive a notification message sent by the wireless local area network discovery and selection device, wherein the notification message carries access parameter information, wherein the access parameter information carries an offload policy message, and wherein the offload policy message is used to instruct to select a wireless access point with a highest signal strength or select a wireless access point in a preset frequency band, and wherein the notification message further carries a second wireless access point list, wherein the second wireless access point list is acquired by the wireless local area network discovery and selection device by acquiring attribute information of each wireless access point in all wireless access point identifiers corresponding to the location information of the terminal upon reception of the registration request and identifying availability of each wireless access point according to the attribute information of each wireless access point in all the wireless access point identifiers corresponding to the location information of the terminal, the second wireless access point list comprises at least one wireless access point identifier available for access by the terminal and attribute information of each wireless access point available for access by the terminal, wherein the attribute information comprises at least one of a signal-to-noise ratio, a load, and throughput, and the offload policy message is used to instruct to select a wireless access point with a highest signal strength, select a wireless access point with a smallest load, or select a wireless access point in a preset frequency band; a processor; and a computer-readable storage medium storing a program to be executed by the processor, the program including instructions for: scanning wireless local area networks in response to receiving the notification message, and acquiring a first wireless access point list, wherein the first wireless access point list comprises at least one wireless access point identifier and signal strength of each wireless access point or a frequency band of each wireless access point in the first wireless access point list or both; and selecting, according to the access parameter information and the offload policy message, a target wireless access point from the second wireless access point list.

15. The terminal according to claim 14 , wherein the program further includes instructions for: determining, after selecting the target wireless access point according to the access parameter information and the offload policy message, that offload fails when the target wireless access point is not detected within a first preset time segment, and disabling a Wireless Fidelity function; or after selecting the target wireless access point according to the access parameter information and the offload policy message, the Wireless Fidelity function when no data traffic of the packet switched data is detected within a second preset time segment.

16. The terminal according to claim 14 , wherein the program further includes instructions for: detecting, after selecting the target wireless access point according to the access parameter information and the offload policy message and when the wireless local area network can be accessed by using the target wireless access point, a speed in the wireless access local network; determining determine whether the speed is lower than a preset speed threshold; and when the speed is lower than the preset speed threshold, disabling the Wireless Fidelity function.

17. The terminal according to claim 14 , wherein the notification message further carries a service set identifier of a wireless access point of an available wireless local area network; wherein the first wireless access point list further comprises a service set identifier of a wireless access point of a wireless local area network corresponding to each wireless access point in the at least one wireless access point identifier; and wherein the program further includes instructions for selecting, according to the offload policy message, the service set identifier of the wireless access point of the wireless local area network, and the first wireless access point list, the target wireless access point from the first wireless access point list.

18. The terminal according to claim 14 , wherein: the program further includes instructions for selecting, according to the offload policy message, the target wireless access point from an intersection of the first wireless access point list and the second wireless access point list.

19. A wireless local area network discovery and selection device, comprising: a receiver, configured to receive a registration request sent by a terminal, wherein the registration request is initiated when the terminal initiates packet switched data to a cellular network, wherein the registration request carries location information of the terminal, and wherein the registration request carries a first wireless access point list, wherein the first wireless access point list is acquired by the terminal by scanning wireless local area networks and the first wireless access point list comprises at least one wireless access point identifier; a processor; and a computer-readable storage medium storing a program to be executed by the processor, the program including instructions for: acquiring access parameter information when a wireless local area network needs to be used to offload the packet switched data in the cellular network, wherein acquiring the access parameter information comprises: acquiring attribute information corresponding to each wireless access point identifier in the first wireless access point list, wherein the attribution information is acquired from one or more access controllers corresponding to each wireless access point identifier in the first wireless access point list, and wherein the attribute information comprises at least one of a signal-to-noise ratio, a load, and throughput; identifying availability of each wireless access point according to the attribute information corresponding to each wireless access point identifier in the first wireless access point list; acquiring a second wireless access point list, wherein the second wireless access point list comprises at least one wireless access point identifier available for access by the terminal and attribute information of each wireless access point available for access by the terminal; and acquiring a preset offload policy information, wherein the preset offload policy information is used to instruct to select a wireless access point with a highest signal strength, select a wireless access point with a smallest load, or select a wireless access point in a preset frequency band; and a transmitter, configured to send a notification message carrying the access parameter information to the terminal so that the terminal selects, according to the access parameter information, a target wireless access point, wherein sending the notification message carrying the access parameter information to the terminal comprises sending a notification message carrying the offload policy information and carrying the second wireless access point list to the terminal, so that the terminal selects, according to the offload policy message, to the target wireless access point from the second wireless access point list.

20. The device according to claim 19 , wherein the program further includes instructions for determining, after receiving the registration request sent by the terminal and before acquiring the access parameter information when the wireless local area network needs to be used to offload the packet switched data in the cellular network, whether the wireless local area network needs to be used to offload the packet switched data in the cellular network.

21. The device according to claim 20 , wherein the program further includes instructions for acquiring, from a network element in the cellular network or a network element in a core network, a service type of the packet switched data and determining, according to the service type, whether the wireless local area network needs to be used to offload the packet switched data in the cellular network.

22. The device according to claim 21 , wherein the program further includes instructions for acquiring, from a home location register, a priority of a user corresponding to the terminal; determining whether the priority of the user corresponding to the terminal is higher than or equal to a preset priority threshold; and determining, when the priority of the user corresponding to the terminal is higher than or equal to the preset priority threshold, that the wireless local area network does not need to be used to offload the packet switched data in the cellular network; or otherwise, determining, when the priority of the user corresponding to the terminal is lower than the preset priority threshold, that the wireless local area network needs to be used to offload the packet switched data in the cellular network.